Tooth and like brushes



Feb. 24, 1942. E. l.. H. sv A 2,274,042

TOOTH`AND LIKE BRUSHES Filed Nov. 18, 1939 2 Sheets-Sheet 1 wl In x 1CD y l "NF/, [i C i 1 1mm/TOR: A l

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` Feb. 24, 1942. I E, L, H cosBY 2,274,042

TOOTH AND LIKE4 BRUSHES Filed Nov. 18, v1939 2 Sheets-Sheet 2 vvswwk'. 1Q Eme LeovoLD ma@ Cosf HTTORNEYS,

Patented Feb. 24, 1942 Eric Leopold Hugo Cosby, London, England Application November 18, 1939, Serial No. 305,184 In Great Britain November 21, 1938 3 claims.

With certain types of tooth, palate plate and like brushes, it is usual to trim the bristles or tufts of Ibristles to different lengths or with an undulating surface, so that some of the bristles or tufts project beyond the other bristles or tufts. Now the stiffness of a bristle depends on the quality and length of a bristle, that is to say a short bristle of one quality is comparatively stiff, Whilst a long bristle of the same quality is more flexible and therefore soft, and consequently to make a brush of this type with equal stiffness throughout the bristles or tufts of bristles, it is necessary to use different qualities of bristles for the short and for the long, and the object of this invention is to make it possible for the bristles or tufts of bristles to be of equal stiffness Without having to use different quality of bristle to Iattain this aim.

According to this invention, the face of the stock of the brush in which the bristles are inserted is of different levels and the bristles or tufts of bristles are trimmed to the same length, whereby a brush of undulating surface is provided in which the bristles or tufts of bristles are all of the same stiffness and can be of the same quality.

The invention will be clearly understood from the following description aided by the examples shown on the accompanying drawings, and in which:

Figure 1 is a plan, Figure 2 a side view partly 'in section, and Figure 3 a section on the line III- III of Figure l showing one example of the invention.

Figure 4 is a plan, and Figure 5 a section on the lines V-V, Figure 4 showing a section example.

Figure 6 is a similar section to Figure 5 showing a modified construction.

Figure 7 is a side view, FigureV 8 a plan, and Figure 9 a section on the line IX-IX of Figure 7 showing a further example, and

Figure 10 a side View of a still further example. According to the example shown in Figures l to 3 of the accompanying drawings, the stock l of the brush is formed with a raised flat portion la across the end for receiving a projecting portion of tufts of bristles 2, and a central raised flat rib ib` of less height than the portion la for receiving a central row or rows of projecting bristles 2a, whilst the lower flat portions lc of the stock l on each side of the rib Ib receive tufts of bristles 2b.

the same length the end tufts 2 will-project beyond the other tufts for cleaning in between the teeth, the centre row of tufts 2a will project a little beyond the side tufts 2b but not so far as the end tufts 2 and take up the worst of the wear which is along the centre of the brush, and

by trimming the tufts of bristles all to the same length they will be of equal stiffness and can be all of the same quality, and at the same time have the undulations of working surface desired in this type of brush.

In Figures 4 and 5, the front raised portion I a only extends partly across the stock I, so that the lower flat surface lc can extend on each side of the raised portion la to receive tufts of bristles 2b.

In Figure 6 the stock I is formed with the raised front portion la and without the rib lb and the tufts 2b extend all over the flat portion Ic.

In Figures 7 to 9, a slightly different type of brush is shown, in which the upper surface of the stock l is formed with a raised portion la at the tip, ya straight flat portion a behind the raised portionand in a parallel plane therewith, and an angled flat portion b leading into the handle 3, the tufts of bristles being trimmed to the same length.

Figure 10 shows a slight modification of Figure 7 in that the portion of the stock I carrying the bristles is in a straight angled line or slightly curved from the base of the raised front portion la to the handle 3.

Although the shape of the toothbrush varies, equal stiffness of each tuft is possible with one quality of bristle through the toothbrush stock conforming to the shape of the head or bristle or tufts of the brush, and so enables the same Now if all the tufts of bristles are trimmed to length and quality of bristle or tufts to be used throughout.

What I do claim Ias my invention and desire to securev by Letters Patent is:

1. A tooth brush comprising a stock having a raised flat portion adjacent to its end, a relatively depressed portion, and a central rib raised from said depressed portion to a level below said raised portion and extending longitudinally of the stock from said raised portion toward the handle, and tufts of bristles inserted in said raised and depressed portions and ribs, said tufts of bristles being all of the same length and presenting at their outer ends a brushing surface which is undulated longitudinally and transl versely of the brush.

2. A tooth brush comprising a stock having their outer ends a brushing surface which is 10 undulated longitudinally of the brush.

3. .A tooth brush comprising a stock having a raised flat portion adjacent to its end and a flat relatively depressed portion inclined upwardly from the base of said raised portion toward the handle, and tufts of bristles inserted in said raised and depressed portions, said tufts of bristles being all of the same length and presenting at their outer ends a brushing surface Which is undulated longitudinally of the brush.

ERIC LEOPOLD HUGO COSBY. 

